1. Field of the Invention
The present invention relates to improved clutch mechanisms for selectively connecting two adjacent rotatable driving and driven members. This invention may be utilized, for example, for engaging the gears or other torque transmitting means in change speed transmissions and the like. This improved clutch mechanism moves a clutch member from a locked engaged position to an unlocked engaged position and maintains this clutch member in the unlocked engaged position at a predetermined torque level until this torque level is exceeded by torque transfer between the driving and driven members.
2. DESCRIPTION OF THE PRIOR ART
Rocker arm clutch mechanisms include a rotatable driving member and a rotatable driven member wherein a carrier is fixed to one of these members, with the carrier having circumferentially spaced rocker arms that are adapted to be rocked radially, on at least one end, by means of a collar and shift yoke, for selective rocking engagement into coupling engagement with adjacent clutch portions on the other of the driving and driven member. This rocker action eliminates the axial shift movement heretofore required and materially reduces the spacing required between the driving and driven members since there is no axial sliding movement of the coupling members but only a radial rocking action.
Rocker arm clutch mechanisms are well known in the art, including those set forth in U.S. Pat. No. 2,447,058 to Dence; U.S. Pat. No. 2,412,208 to Dence; U.S. Pat. No. 2,558,656 to Lapsley; U.S. Pat. No. 2,584,032 to Lapsley and U.S. Pat. No. 3,024,885 to Dence et al. While all the structures shown in these patents are readily workable, none of them suggest or teach the improvement of this invention, i.e., means for axially shifting the clutch collar to an unlocked engaged position intermediate the locked neutral and locked engaged positions and yieldingly maintaining the collar in the unlocked engaged position at a predetermined torque level until this torque level is exceeded by the torque transfer between the driving and driven members. Basically, this improvement allows unlocked engagement between the driving and driven members but permits disengagement therebetween if the torque exceeds a predetermined level.